1. Field of the Invention
This invention relates to footwear and more specifically to footwear having an improved insole.
2. Brief Description of the Prior Art
It is known in the prior art to produce footwear by the lasting process. In one type of lasting, referred to in the industry as flat lasting, an upper is placed on a last and the end portion of the upper is tightened around the periphery of the insole and cemented to the bottom of the insole. The insole provides a platform during this lasting process and it must be of sufficient thickness, rigidity and strength to withstand the force of the upper end portion as it is tightened around the periphery of the insole and cemented to the insole bottom. At the same time, it is desirable that the insole be light and flexible. There have been various approaches to providing improved insoles for use in such footwear lasting including, for example, the insoles disclosed in U.S. Pat. Nos. 2,144,340; 2,809,450; and 5,105,564.
After the upper and insole are lasted, an outsole is attached to the insole by molding the outsole to the insole, or by other means, and the last is removed from the completed shoe. Other intermediate steps that may occur during the lasting process include softening the upper in a heat chamber, forming a box toe, and trimming excess cement from the bottom of the insole.
It is also known in the prior art to include a cushioned insert on an insole to provide cushioning for the wearer of the footwear. In one such prior art footwear sold by Georgia Boot Inc., (the predecessor of the assignee of the present invention) under the name “Comfort Core Welt”, a bottom extension on a cushioned insert was inserted into an opening in the insole. This footwear was produced by a lasting method known as the welt lasting method and the footwear included an outsole which was cemented to the footwear.
In the past, footwear outsoles were formed of light weight blown polyurethane material. However, no such footwear which included an insole having an opening therein included a polyurethane outsole. It is believed that the reason such otherwise desirable light weight polyurethane outsoles were not used with insoles having openings therein, was because an objectionable amount of polyurethane would enter the footwear through the openings in the insole when the polyurethane formed the outsole.